Traffic segregation on a single carriageway

Dans le document Guidelines for cycle facilities (Page 46-50)

8 Link section facilities

8.2. Recommendations for cross-sections

8.2.2. Traffic segregation on a single carriageway

Definition of a cycle lane

According to the French Highway code definition in article R.110-2, the term cycle lane used with reference to a roadway comprising several lanes, designates the one that is reserved for use by bicycles or tricycles. Thus it is part and parcel of the carriageway.

This definition implies that cycle lanes are by force one-way and marked on the carriageway in the direction of the general traffic flow. Its main strength is that it allocates a specifically dedicated space to cyclists.

Cycle lane signage and colouring

The statutory white T3 5u marking is accompanied by a white figure depicting a cyclist. This marking may be supplemented by the colour green in areas that should be limited to the strict minimum to avoid any risk of skidding. The mandatory vertical sign is the C113 or B22 panel that indicate whether or not use of the facility is recommended or compulsory for cyclists.

The criteria for choosing between hardstrips and cycle lanes

According to the regulations, since cycle lanes are defined as a carriageway path, they are not part of the safety zone measured from the carriageway edge. The ARP recommends a 4-m width for safety zones on existing routes. Motorists out of control of their vehicles will use cycle lanes in the same way as they will use hardstrips. Thus, in practice the effective safety zone is not reduced. The choice between a hardstrip and a cycle lane is not solely governed by the issue of cost or surcharge resulting primarily from the dimensional aspect of

T H E T O O L K I T

The Rhone “départment”t has opted for cycle lanes along its high-density touring cycle arteries (CG 69)

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carriageway structure, nor is it necessarily linked to a problem of site-specific land availability. First and foremost, this choice stems from road managers’

stated willingness to encourage or discourage cyclists from using this route. Generally, this choice will be dictated by the existence or absence of other safer, more pleasant alternative routes, traffic density and driving speeds along the particular section, and the physical possibilities of equipping and eventually maintaining the facility. The preference of a hardstrip over a cycle lane should be determined on an individual case basis, depending on the route, its occupancy level, cross-section and usages, whilst bearing in mind that the continuity of routes does not necessarily imply the continuity of their component facilities. The upkeep of lanes and hardstrips is easier than cycle paths : road managers must be even more demanding about cycle lane upkeep quality than they are for hardstrips.

Hardstrips suffice for most of the road network

Cyclists offered the possibility of riding on a hardstrip when they want to or consider it essential for safety reasons, gives seasoned cyclists comfort and considerable flexibility, especially when HGVs overtake them.

Cycle lanes are preferable for some cyclists or specific points

However, in popular or up-and-coming cycle touring areas hardstrips are unsatisfactory.

Preference will be given to consigning part of the shoulder to a cycle lane strictly set aside for cycle traffic. For example, it is preferable to provide links between a conurbation exit and the greenway with a cycle lane combined with a space earmarked primarily for pedestrians.

In special situations, choosing a cycle lane would seem more appropriate even if it is restricted to the danger zone : for example uphill along a narrow route or on a wide, winding road, and whenever road managers identify sections where the space given over to cyclists must be clearly marked to avoid any risk of conflict or dangerous manoeuvres

by motorised vehicles : poor visibility on bends, carriageway narrowing on the approach to particular points, etc. Bypasses are recommended on bends to avoid cyclists being hemmed in by other road users.

The project owner should seize the opportunity of redesigning the cross-section. This is because when bilateral cycle lanes are built along a route outside the conurbation, traffic lane widths are reduced to 3.25 m, or even 3 m. There are two particularly interesting and immediate outcomes worth mentioning : 1) private car driving speeds are reduced, which is beneficial to overall road safety on a route and 2) the impact on the project’s global savings. A mean saving of one metre of shoulder improvement can be made on a cross-section per linear metre of equipped roadway.

The width required for cycling comfort

The Highway Code stipulates that a vehicle should not get closer than 1.5 m to a cyclist in the open countryside.«To overtake (a cyclist) the motorist must pull out sufficiently to eliminate the risk of hitting the user s/he wishes to overtake. Whatever happens, lateral clearance of no less than one metre must be given in conurbations and one and a half metres outside conurbations from all animal-drawn vehicles, two-or three-wheeled vehicles, pedestrians, horse-riders and animals» (art. R.414-4). The demarcation of a cycle lane or creation of a hardstrip to make cycling

T H E T O O L K I T

Bypass : the cyclist is protected behind the separator (FFCT S. Jackson)

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easier must not lead drivers to flout this precautionary principle. Thus cycle lane and hardstrip widths of the order of 1.25-1.5 m are recommended, except at particular points where very occasionally a narrower width could be tolerated rather than abruptly interrupting the facility and continuity of the route in a recognised danger zone.

How particular points are handled

Logic has it that cycle lanes or hardstrips run either side of the roadway. However, if not enough land is available, the designer will have to question the advantage of making a single facility instead of two very narrow curb lanes. The topography, distribution of intersections and particular points along the route have to be borne in mind when deciding on which is the most apt side of the road to develop : it is advisable to give preference to the uphill direction as cyclists’ efforts are greater and their speeds reduced, or another key alternative on the inside of a tight bend where vehicles tend to «clip»

the shoulder to iron out the bend… Mountain routes tend to be equipped in this way with a hardstrip on the ascent. Many racing cyclists are very keen on attacking routes with steep hills : while their speed is reduced on the ascent by the effort made, their speed on the descent is often similar to that of other users.

Cycling policy in the Lower Rhine : a prime exponent of multicriteria analysis Whenever possible the department of the Lower Rhine plumps for cycle lanes, sometimes even narrow lanes (1-1.2 m excluding marking), because this enables reserved spaces to be marked out for cycles and clearly demonstrates its political determination to give cyclists a space of their own.

However, there are some twenty or so kilometres of hardstrips where special situations prevail :

• hardly 1 metre of space deemed insufficient for creating cycle lanes. For example : RD 919 between Haguenau and Schweighouse (~8K VPD);

• proximity of a greenway running parallel along a disused railway line, presence of heavy traffic with many HGVs on the trunk road and long bends enabling speeds to pick up despite limited visibility distances. Conclusion – no display of the cycle route and thus merely a 1.5 m wide hardstrip. For example : the RD 422 between Molsheim and Marlenheim or the RD 263 between Haguenau and Surbourg (~12K-14K VPD) ;

• hardstrips 1.5 m wide chosen because of parallel routes on minor roads, and high likelihood of tractor soiling in a mainly farming area. For example : RD 419 between Brumath and Pfaffenhoffen (~4K-6K VPD);

This “départment” has decided not to differentiate between cycle lanes and hardstrips on the highway structure plan, at the new shoulders to be constructed. When traffic flow requirements justify upgrading, hardstrips can be fairly easily converted into cycle lanes at any time by using a traffic bylaw, signage and road markings.

T H E T O O L K I T

Wouldn’t it have been preferable to leave things as they were ? (FFCT J. Fourna)

The lane turns into a path on ascending bends (FFCT)

T H E T O O L K I T 47

Hardstrips Cycle lane

Functions Integral part

of the shoulder

Traffic lane allocated to cyclists

Traffic flow

Driving authorised for cyclists ; pedestrians urged to use the hardstrip if it can be negotiated

Cyclists and possibly moped riders if authorised ; pedestrians on the

edge if the hardstrip cannot be walked on ; optional for cyclists

(saving exceptions)

Emergency stop for vehicles Tolerated Tolerated

Parking

May be authorised when conditions apply (signage, marked bays)

Not authorised

Features

Technical structure Not necessarily equivalent to the cariageway

Generally equivalent to the carriageway

Wearing course

Wear as good as the carriageway but not necessarily of

the same kind (primarily difference in shade)

Generally identical to that of the carriageway

Width 1.25-1.5 m surfaced

(see ARP table § 8.2.1.2.) 1.25-1.5 m

Signage Nearside line T2 3u,

nothing vertical

T3 5u road marking and vertical (C113 or B22a) signs

Green Not applicable Possible (circular dated 15/6/1996)

Cleaning

Cleaning, repairs May be less frequent and not as thorough as for the roadway

Regular because it is a major user expectation

Summary of selection criteria : hardstrips and cycle lanes

Hardstrips that easily convert into cycle lanes (CG 69) A lane that is almost as comfortable as a path (non-statutory

marking) (Cete NPC)

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8.2.3.

Reserved lane facilities

Dans le document Guidelines for cycle facilities (Page 46-50)